1. Field of the Invention
This invention relates to an oscillator for use in various kinds of electric products.
2. Description of the Related Art
Oscillators are widely used as local oscillators in communication apparatuses or the like. FIG. 5 shows an example of the conventional oscillators of this kind.
In a lower casing member 1 shown in FIG. 5, a vibration plate 2 is provided. The vibration plate 2 has a plate-like shape, as shown in FIG. 6, and electrodes 3 are provided on obverse and reverse surfaces of the vibration plate 2. An upper case 4 is so shaped as to be placed over an opening in the upper surface of the lower casing member 1 to sealingly close the opening.
In the above-described arrangement, the vibration plate 2 is fixed in the lower casing member 1 by a bonding strength of an electroconductive adhesive 5.
The thus-constructed conventional oscillator entails a problem that it is very difficult to stabilize the vibration of the vibration plate 2. That is, the oscillator of this kind is very small and, naturally, the lower casing member 1 and the vibration plate 2 are small. Therefore, it is very difficult to correctly set the vibration plate 2 in a predetermined position in the lower casing member 1. As a result, a peripheral portion of the vibration plate 2 contacts an inner surface of the lower casing member 1, so that the stability of vibration is thereby reduced.